Surgical Technique and Outcome of Custom Joint-Sparing Endoprosthesis as a Reconstructive Modality in Juxta-Articular Bone Sarcoma

Revision for Solid-Body Breakage of the 3D-Printed Implant Following Joint-Sparing Surgery: A Technical Note

BACKGROUND

The advent of three-dimensional (3D)-printed custom-made implants has revolutionized orthopaedic surgery, particularly in limb- and joint-sparing surgeries. However, clinical experience in the revision for 3D-printed implant breakage is lacking, and the revision surgery remains challenging. This study reported the revision of proximal tibial prosthetic reconstruction necessitated by solid-body breakage of a 3D-printed implant, aiming to detail the surgical techniques and evaluate postoperative outcomes.

CASE PRESENTATION

A patient diagnosed with osteosarcoma underwent joint-sparing surgery with a 3D-printed implant, but implant breakage occurred during subsequent follow-up. The initial implant was broken into two parts: the proximal implant breakage part (IBP) integrated with the host bone and the distal IBP left in the prosthetic component. Four revision protocols were devised, each based on one of the four hypothesis results of taking out the initial implant. A new custom-made implant and a series of assistance devices ("positioning devices," "drill devices," "tap devices," and "separator devices") were specifically prepared for revision surgery. The proximal IBP was taken out from the host bone, but the distal IBP was not taken out from the initial prosthetic component. The patient received the new custom-made implant for reconstruction, with the knee joint preserved. The patient recovered uneventfully after revision surgery and achieved satisfactory function. The Musculoskeletal Tumor Society was 28 at the last follow-up. No complications were detected during the follow-up period.

CONCLUSION

Comprehensive preoperative planning and preparation, enabling the surgeon to effectively address intraoperative challenges, are crucial for the successful revision of 3D-printed implant breakage. It is feasible to re-implant a 3D-printed custom-made implant, demonstrating satisfactory clinical and functional results.

Intercalary Prosthetic Reconstruction with Three-Dimensional-Printed Custom-Made Porous Component for Defects of Long Bones with Short Residual Bone Segments After Tumor Resection

BACKGROUND

Intercalary reconstruction for patients with short residual bone segments remains challenging. Three-dimensional (3D)-printed custom-made porous implants are a promising technique for short-segment fixation in these patients. This study aims to evaluate the efficiency of 3D-printed custom-made porous components (3DCPCs) for short-segment fixation, focusing on prosthesis survivorship, radiographic results, and potential complications.

METHODS

This retrospective study involved 39 patients who underwent intercalary prosthetic reconstruction with 3DCPCs after tumor resection of the femur, tibia, or humerus from June 2015 to October 2020. Segment bone loss involved the femur (n = 15), tibia (n = 16), and humerus (n = 8), leaving 78 residual bone segments. There were 46 short segments requiring 46 3DCPCs and 32 segments with the ability to accommodate 32 off-the-shelf standard uncemented stems for prosthesis fixation. Clinical and functional outcomes were evaluated. Prosthesis-overall survivorship and prosthesis-specific survivorship were analyzed using Kaplan-Meier survival analysis. Radiographic results and modes of failure of using this technique were also examined.

RESULTS

The mean follow-up was 41 months. The prosthesis-overall survivorship was 87.2% and 84.6% at 2 and 5 years, respectively. The prosthesis-specific survivorship was 92.1% and 89.5% at 2 and 5 years, respectively. There was not a substantial difference in prosthesis survivorship among the femur, tibia, and humerus. The average MSTS score was 26.2, ranging from 22 to 28. The radiographic evaluation results revealed excellent or good interface (38/46) in most of the 46 porous components. A total of 38 of 46 bone segments' remolding demonstrated no change. In total, seven patients (16.3%) had complications requiring further surgery.

CONCLUSION

The prosthesis survivorship of using 3DCPCs for short-segment fixation is similar or better compared to other studies involving intercalary prosthetic reconstruction with short-segment fixation. Radiographic evaluation revealed good osteointegration and avoidance of stress shielding. Overall, intercalary prosthetic reconstruction with 3DCPC is a feasible modality for patients with short residual bone segments after tumor resection.

Neoadjuvant Chemotherapy and Expandable Prosthesis Reconstruction to Treat Osteosarcoma around the Knee in Children

OBJECTIVE

Survival and reconstruction in osteosarcoma is quite challenging. The study aimed to investigate the prognosis in patients treated with neoadjuvant chemotherapy and determine the clinical outcomes of expandable endoprosthesis reconstruction in children.

METHODS

From January 2009 to December 2014, we retrospectively analyzed 29 skeletally immature children (mean age, 10.5 years; range, 6-15 years) with osteosarcoma around the knee. Of the 29 patients who underwent neoadjuvant chemotherapy and limb salvage surgery, an expandable prosthesis was implanted for reconstruction. No patients were missed during follow-up. The evaluation index involved follow-up time, complication, functional results, and lengthening procedures. The survivorship and recurrence were assessed by GraphPad Software, and the function was evaluated by the Musculoskeletal Tumor Society (MSTS) scoring system.

RESULTS

A mean follow-up time was 8.9 years (range, 6-12 years), and the overall 5-year survival was 89.1% based on Kaplan-Meier analysis. Three patients suffered a relapse and one underwent amputation. Lung metastasis developed in one patient. At 6 months after the operation, patients had a mean MSTS score of 27 points (range, 24-29). Two patients underwent revision surgery, one for implant infection and one for aseptic loosening. Prognosis is correlated with alkaline phosphatase change after treatment.

CONCLUSIONS

Chemotherapy scheme and limb salvage can achieve high survival rates. This expandable prosthesis was associated with good function and low complication rates. The character of expandability could be a method to overcome discrepancies in the growth period.

Case Report: 3D-Printed Prosthesis for Limb Salvage and Joint Preservation After Tibial Sarcoma Resection

Introduction

Reconstruction of massive tibial defects in ankle joint-preserving surgery remains challenging though biological and prosthetic methods have been attempted. We surgically treated a patient with only 18-mm distal tibia remaining and reconstructed with a unique three-dimensional printed prosthesis.

Case Presentation, Intervention, and Outcomes

A 36-year-old male presented to our clinic with complaints of gradually swelling left calf and palpable painless mass for five months. Imageological exam indicated a lesion spanning the entire length of the tibia and surrounding the vascular plexus. Diagnosis of chondrosarcoma was confirmed by biopsy. Amputation was initially recommended but rejected, thus a novel one-step limb-salvage procedure was performed. After en-bloc tumor resection and blood supply rebuilding, a customized, three-dimensional printed prosthesis with porous interface was fixed that connected the tumor knee prosthesis and distal ultra-small bone segment. During a 16-month follow-up, no soft tissue or prosthesis-related complications occurred. The patient was alive with no sign of recurrence or metastasis. Walking ability and full tibiotalar range of motion were preserved.

Conclusions

Custom-made, three-dimensional printed prosthesis manifested excellent mechanical stability during the follow-up in this joint-preserving surgery. Further investigation of the durability and rate of long-term complications is needed to introduce to routine clinical practice.

[Update on 3D printing in the surgery of musculoskeletal tumors]

The importance of 3D printing applications in the surgery of musculoskeletal tumors has increased in recent years. Even prior to the era of 3D printing, computer-assisted techniques, such as navigation, have proved their utility. Due to the variable appearance of bone tumors, there is a need for individual solutions. The 3D printing can be used for the development of anatomical demonstration models, the construction of patient-specific instruments and custom-made implants. For these three applications, different regulatory hurdles exist. Especially for the resection of pelvic tumors, 3D printing technologies seem to provide advantages due to the complicated anatomy and the proximity to relevant neurovascular structures. With the introduction of titanium printing, construction of individualized implants that fit exactly into the defect became feasible.

Intercalary reconstruction of the distal femur with or without physeal preservation: results and impact on limb growth

PURPOSE

Allograft reconstruction with or without vascularized fibula can be a valuable solution to treat childhood intercalary tumours of the distal femur. We aimed to assess the oncological status, complication rate and survival of distal femur intercalary reconstruction after trans-metaphyseal (TMR) and trans-epiphyseal resection (TER). We also evaluated the impact of distal temporary graft fixation on skeletal growth after TMR.

METHODS

We retrospectively reviewed 23 skeletally immature patients affected by distal femur osteosarcoma (18) and Ewing sarcoma (5). Mean patients age was 10.3 years. In 11 cases, TMR was performed with physis preservation and temporary distal graft fixation. In 9 patients, TER was performed with growth plate sacrifice. The last 3 cases were treated with TMR and sliding plate fixation.

RESULTS

Mean follow-up was 8.4 years. No deaths occurred, but 3 patients presented lung metastasis and 2 cases presented local recurrence in soft tissues. 10 implant-related complications occurred, all surgically treated. At skeletal maturity, mean femoral dysmetria was 2.3 cm after TMR and temporary epiphysiodesis, and 3.1 cm after TER. In TMR group, a strong trend towards physeal recovery was observed after epiphyseal screws removal (p = 0.061), but valgus deformity in distal femur was more frequent (p = 0.049). MSTS score was good or excellent in all patients, with no statistically significant difference between TMR and TER.

CONCLUSIONS

Intercalary graft reconstruction after TMR and TER allows good local disease control and excellent functional results with long-term follow-up. Temporary distal fixation might reduce the final limb discrepancy after TMR, but valgus deformity could develop.

LEVEL OF EVIDENCE

Level IV.

Computer Navigation and 3D Printing in the Surgical Management of Bone Sarcoma

The long-term outcomes of osteosarcoma have improved; however, patients with metastases, recurrence or axial disease continue to have a poor prognosis. Computer navigation in surgery is becoming ever more commonplace, and the proposed advantages, including precision during surgery, is particularly applicable to the field of orthopaedic oncology and challenging areas such as the axial skeleton. Within this article, we provide an overview of the field of computer navigation and computer-assisted tumour surgery (CATS), in particular its relevance to the surgical management of osteosarcoma.

Salvage Reconstruction With the Masquelet Technique Following Wide Resection for Chondrosarcoma of the Proximal Femoral Metaphysis: A Case Report

BACKGROUND

Bone reconstruction following a wide resection for a malignant musculoskeletal tumor remains challenging, especially for an intercalary defect following the resection of a metaphyseal lesion.

CASE REPORT

Here, we describe a surgical procedure using the Masquelet technique for the biological reconstruction of a huge subtrochanteric bone defect following failed pasteurized autologous bone grafting for a conventional chondrosarcoma of the proximal femoral metaphysis with a subtrochanteric pathological fracture. The patient, a 43-year-old Japanese male, was able to walk without a cane or a brace at 15 months after the final operation (International Society of Limb Salvage score, 86.7%).

CONCLUSION

This procedure should be considered as one of the reconstruction options following the wide resection of malignant bone tumors located in the metaphysis.